Infectious complications and especially anastomotic leakage severely impede the recuperation of patients following colorectal cancer surgery. When the normal gut barrier fails such as in anastomotic leakage, pathogenic microorganisms like Gram-negative bacteria enter the circulation and may cause severe sepsis which is associated with considerable mortality. Moreover, anastomotic leakage has a negative impact on colorectal cancer prognosis. Selective decontamination of the digestive tract (SDD) is a prophylaxis regimen that employs oral nonabsorbable antibiotics to eradicate pathogenic micro-organisms like Gram-negative bacteria.